Molybdenum doped porous Ni–Cu cathodes are conveniently prepared by powder metallurgy in this work. The microporous structure of the porous Ni–Cu based cathodes has a certain correlation with the content of molybdenum, which consequently influences the electrocatalytic behavior as electrode materials. Electrocatalytic performance of the prepared cathodes has been investigated by hydrogen evolution reaction in 6.0 mol L⁻¹ KOH solution. It is demonstrated that the Mo doped porous Ni–Cu cathodes exhibit a superior electrocatalytic activity for HER over a binary porous Ni–Cu cathode, among which the porous Ni–Cu with 6.0 wt% Mo shows the highest intrinsic activity and an ascendant stability during HER. Although the porous Ni–Cu (with 9.0 wt% Mo) expresses the highest activity, a gradual decline of the current density for HER in long-term operation is found, which is due to the dissolution of Mo from the porous skeleton in alkaline solution.

Porous Ti3SiC2 was fabricated with high purity, 99.4 vol %, through reactive sintering of titanium hydride (TiH2), silicon (Si) and graphite (C) elemental powders. The reaction procedures and the pore structure evolution during the sintering process were systematically studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). Our results show that the formation of Ti3SiC2 from TiH2/Si/C powders experienced the following steps: firstly, TiH2 decomposed into Ti; secondly, TiC and Ti5Si3 intermediate phases were generated; finally, Ti3SiC2 was produced through the reaction of TiC, Ti5Si3 and Si. The pores formed in the synthesis procedure of porous Ti3SiC2 ceramics are derived from the following aspects: interstitial pores left during the pressing procedure; pores formed because of the TiH2 decomposition; pores formed through the reactions between Ti and Si and Ti and C powders; and the pores produced accompanying the final phase synthesized during the high temperature sintering process.